Method and apparatus for header setting in a wireless communications system

Abstract

A method for setting a header of a protocol data unit in a radio link control layer of a wireless communications system, wherein a length indicator consisting of multiple bits is used to indicate an ending position of a first service data unit carried by a first PDU, includes under a predefined condition, not inserting a length indicator for a second SDU carried by a second PDU in the header of the second PDU.

What is claimed is: 
     
       1. A method for setting a header of a protocol data unit (PDU) carrying at least a last segment of a service data unit (SDU) in a radio link control layer of a wireless communications system, the method comprising:
 forming a SDU; 
 forming a PDU to carry at least a last segment of the SDU, wherein the PDU includes a header, in which a length indicator of multiple bits indicating an ending position of the SDU is inserted when a length of the PDU is equal to a predefined maximum PDU length and the length indicator is not inserted when the length of the PDU is smaller than the predefined maximum PDU length; wherein the length indicator is not inserted in a header of any other PDU when the length of the PDU is smaller than the predefined maximum PDU length; 
 enabling a decrease of a length of the header of the PDU by not inserting the length indicator in the header; and 
 transmitting the PDU to a peer receiver. 
 
     
     
       2. A communications device of a wireless communications system utilized for setting a header of a protocol data unit (PDU) in a radio link control layer, for decreasing the header length, the communications device comprising:
 a control circuit for realizing functions of the communications device; 
 a processor installed in the control circuit for executing a program code to operate the control circuit; and 
 a memory coupled to the processor for storing the program code; 
 wherein the program code comprises:
 forming a SDU; 
 forming a PDU to carry at least a last segment of the SDU, wherein the PDU includes a header, in which a length indicator of multiple bits indicating an ending position of the SDU is inserted when a length of the PDU is equal to a predefined maximum PDU length and the length indicator is not inserted when the length of the PDU is smaller than the predefined maximum PDU length; wherein the length indicator is not inserted in a header of any other PDU when the length of the PDU is smaller than the predefined maximum PDU length; 
 enabling a decrease of a length of the header of the PDU by not inserting the length indicator in the header; and 
 transmitting the PDU to a peer receiver.